Keysight Technologies L4490A, Руководство пользователя

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138 Keysight L4490A/L4491A User’s Guide
Additional Operating Information Using Single-Coil Switches and Attenuators
Using Single-Coil Switches and Attenuators
Some microwave

switches require a single drive (coil). With single coil devices,
note that the channel numbering is not consecutive across all channels in a bank
(see Chapter 2 “Channel Numbering).
The L4490A/L4491A can provide single coil devices with either pulsed or
continuous drive current. Settings and parameters for continuous drive mode are
given in the next section.
Continuous Drive Mode
Driving non-latching devices requires a power supply capable of handling
sustained high current requirements. You may only use continuous drive current
with channels configured for single drive. Additionally, to prevent an overcurrent
condition within the power supply, care must be taken when operating more than
one continuous drive at a time. The drive type may be configured as either TTL or
open-collector.
Using Continuous Drive
Figure 5-2 illustrates the continuous drive signals for two channels (switches)
and the relationship of the drive parameters to the power supply requirements.
Figure 5-2. Continuous Drive Signals.
As shown in the figure, the drive signal is initially applied to channel 1. Drive is
applied to channel 2 only after a power supply recovery period has elapsed
T(Recovery).
The power supply recovery time can be set for each channel, and is set to
0.0 ms during a bank preset (Chapter 4). The recovery time can be changed
using the command:
T(Setttle)
T(Recovery)
Drive Ch 1
Drive Ch2
Start Drive
Channel 1
Start Drive
Channel 2
Channel 1 Position
Indicators Evaluated